1. Field of the Invention
The present invention relates to a resin composition comprising a polyarylene sulfide (hereinafter referred to as PAS) and an inorganic filler, and to moldings and connectors made of it. More precisely, the invention relates to a resin composition comprising PAS and an inorganic filler, of which the moldings are burred little and which has high weld strength and good flow moldability, and also to moldings and connectors made of the composition.
2. Description of the Related Art
PAS is known as an engineering plastic with high mechanical strength, good heat resistance and good chemical resistance, and moldings of a resin composition as prepared by mixing and kneading PAS and an inorganic filler have many applications in various fields.
However, it has heretofore been said that the resin composition is defective in that its moldings are burred.
Various methods have been proposed for reducing the burrs around the moldings of the composition. For example, one method comprises thermally crosslinking the resin to thereby introduce many branches into the resin. The method could reduce the burrs around the moldings of the resin composition, but the mechanical properties of the moldings are lowered and the resin composition would produce gas when decomposed (see JP-A 64-9266).
In order to compensate for the defect of the thermally-crosslinked PAS, a branched PAS has been proposed, which is prepared by adding a branching agent such as trichlorobenzene or the like to the reaction system followed by polycondensing the resulting system (see JP-A 51-144497). The strength of the branched PAS could be higher than that of the thermally-crosslinked PAS, but is lower than that of a linear PAS. Therefore, one often hesitates in using the branched PAS in the field of resin moldings that are required to have few burrs and have high strength.
Another branched PAS has been proposed, for which a branching agent is added to the reaction system within a period of about 75 minutes before the completion of polycondensation to give a branched PAS (see JP-A 55-28217), but this is faced with the same problem as above.
Still other techniques have been proposed of compounding PAS with any other resin into composites (see JP-A 4-213357, etc.), or copolymerizing PAS (see JP-A 8-134352, etc.), or modifying PAS (see JP-A 5-170908, etc.). However, these could not still satisfy the requirements of reducing the burrs around the resin moldings and of increasing the mechanical strength of the resin moldings.
In addition to their drawback of giving burrs around their moldings, the resin compositions noted above are further problematic in that their weld strength is low and their fluidity is poor. Therefore, it is desired to solve the problems with those resin compositions.